<?php 
header("Content-type: text/xml; charset=utf-8"); 
echo '<?xml version="1.0" encoding="utf-8" ?> ';
$parrams = $_GET;

unset($parrams['sign']);

	 function generateSign($params){
		ksort($params);
		$stringToBeSigned = 'sandboxa39dd41f8b7eba4be35728557';
		foreach ($params as $k => $v)
		{
			if("@" != substr($v, 0, 1))
			{
				$stringToBeSigned .= "$k$v";
			}
		}
		unset($k, $v);
	return md5($stringToBeSigned);
	}
echo '<sign>';
echo strtoupper(generateSign($parrams));
echo '</sign>';

?>